The present invention relates to a molded closure cap for sealing a container and more particularly to a closure cap which is formed in a molding operation where portions of the cap are formed of one plastic and where other portions are formed of another plastic. The same molding dies or plungers are used with different nozzles for the two plastic materials.
There are a number of plastic closure caps which are presently formed by a molding operation where the container engaging threads and other portions are formed in a single mold. Most closure caps of this type are formed from one type of plastic material which is used for the complete closure. Other closure caps are made of two or more plastic materials and the different portions are formed by successively activated plungers or dies.
The closure cap of the present invention uses different plastic materials for the hard and softer portions of the cap such as softer plastic materials for the sealing portions of the closure cap. The invention, however, includes a molding method and means where a single mold is used but where the differing plastic materials are supplied to the single molding means through separate nozzles and during successive spacing motion of the molding dies or plunger.
Thus, the present invention includes improved closure molding means where differing plastics with differing characteristics are used in the molding operation without a change of the molding plunger or dies.
Accordingly, an object of the present invention is to provide an improved method and means for forming a closure cap having portions formed of plastic materials of differing characteristics and to the improved closure thus formed.
Another object of the present invention is to provide an improved method and means of molding.
Another object of the present invention is to provide an improved closure cap having portions formed of differing plastic materials and to the method and means of its manufacture.
Another object of the present invention is to provide a novel closure cap having container engaging portions and sealing portions formed of plastic of differing characteristics.
Other and further objects of the present invention will become apparent upon an understanding of the illustrative embodiments about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.